If you read the manifesto such as it is he was looked for a round that would penetrate and then break into fragments not pass through, that is why he chose the AR-15 (less barrel heating) and the round (fragmenting after impact.
There fore a minimum of pass through kill shots can be anticipated as well as the folks were running not standing still. 52 targets is a huge clump of people but when they run he will have misses, and he only had 30 rounds to net the 52 people total
yes i did read it, and he doesn’t know what he’s talking about... 8m3 is simply a hollow point 7.62x39
8M3 “Effect” 7.62x39cal by TulAmmo...This is some of the most sought after 7.62x39 ammunition and we have so very little of it available right now....at this low price! This 7.62x39 is a 124grn Hollow Point 8M3 bullet with steel case and non-corrosive berdan primer.